Printer and ink cartridge attached thereto

ABSTRACT

In a printer of the present invention, an EEPROM that carries out sequential access and has a relatively small storage capacity is applied for storage elements mounted on both black and color ink cartridges, which are detachably attached to the printer. Pieces of information relating to each ink cartridge, for example, pieces of information on remaining quantities of respective inks in the ink cartridge, are stored in the storage element of the ink cartridge. A format of addressing adopted in the storage elements of the Ink cartridges is different from that adopted in an EEPROM incorporated in a printer main body of the printer. A control IC provided in the printer accordingly converts the storage format of addressing, before writing the information into the storage elements of the ink cartridges. In the printer, a RAM is mounted with the control IC on a carriage, and the pieces of information to be written into the storage elements of the ink cartridges are temporarily registered in the RAM. The pieces of information are then written into the respective storage elements of the black and color ink cartridges, for example, at a timing of a power-off operation. The signal lines and the memory used in the course of writing the information into the storage elements are identical with the signal lines, through which print data are transmitted to a print head mounted on the carriage of the printer, and the memory, in which the print data are stored. The arrangement of the present invention reduces the manufacturing cost of the ink cartridge and also enables size reduction of the whole printer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of copending application Ser. No.10/197,408, filed on Jul. 18, 2002, which is a continuation ofapplication Ser. No. 09/449,732, filed on, Nov. 26, 1999, now U.S. Pat.No. 6,631,967.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a printer with an ink cartridgeattached thereto that carries out printing by the unit of dots, as wellas to an ink cartridge detachably attached to a main body of theprinter. More specifically the invention pertains to a technique ofstoring information into the ink cartridge.

2. Description of the Related Art

The printing apparatus like the ink jet printer and the ink jet plottermainly includes an ink cartridge, in which one or plural inks are kept,and a printer main body with a print head to carry out actual printingoperations on a printing medium. The print head transfers ink fed fromthe ink cartridge onto the printing medium, such as printing paper, soas to implement printing on the printing medium. The ink cartridge isdesigned to be detachably attached to the printer main body. A new inkcartridge has a predetermined quantity of ink kept therein. When the inkkept in an ink cartridge runs out, the ink cartridge is replaced with anew one. Such a printing apparatus is arranged to cause the printer mainbody to calculate the remaining quantity of ink in the ink cartridgebased on the amount of ink transferred from the print head and to informthe user of a state of running out of the ink, in order to prevent theprinting procedure from being interrupted by the out-of-ink.

The data on the remaining quantities of inks are generally stored onlyin the printer main body or in a printer driver that controls theprinter. In the event that a first ink cartridge is replaced with asecond ink cartridge in the course of the printing operation, theinformation relating to the first ink cartridge, such as the data on theremaining quantities of inks, are thus lost or made wrong.

One proposed technique to solve this problem utilizes a non-volatilememory provided in the ink cartridge and causes the required data, forexample, the data on the remaining quantities of inks, to be writtenfrom the printer main body into the non-volatile memory (for example,JAPANESE PATENT LAID-OPEN GAZETTE No. 62-184856). In the case ofreplacement of the ink cartridge during the printing operation, thistechnique ensures the storage of the data on the remaining quantities ofinks.

The ink cartridge attached to the printer is expendable. A non-volatilememory generally used in the printer, for example, a large-sized,expensive non-volatile memory having a relatively large storage capacityof several kilobytes and more than ten terminals, is not applicable forthe ink cartridge. Using such a non-volatile memory makes the inkcartridge undesirably bulky and increases the manufacturing cost of theexpendable ink cartridge, which is abandoned after the ink kept in theink cartridge runs out.

One proposed technique accordingly applies a small-sized specialnon-volatile memory having a relatively small storage capacity for theink cartridge. The non-volatile memory with only several terminalsadopts a specific format of addressing, which is different from theformat of addressing adopted in the general non-volatile memories. Thisaccordingly arises another problem of difficulty in handling.

In the case where the different format of addressing is adopted, thecomputer that controls the writing operation of data may carry outconversion of the format of addressing. In the case of an ink cartridgehaving an ink reservoir, in which a plurality of different inks arekept, and holding required pieces of information, for example, pieces ofinformation on the amounts of ink consumption, independently with regardto the respective inks, however, there are relatively long data lengthsto be written and the address conversion requires an undesirably longtime. Such a disadvantage is not negligible since it may cause all thedata to be not rewritten when no sufficient time period is provided forthe address conversion, for example, at the time of forcible cut-off ofpower supply.

The problems discussed above arise in any printing apparatus that doesnot directly measure the remaining quantity of ink or the amount of inkconsumption in an ink cartridge but causes the printer to compute suchdata, and in an ink cartridge attached thereto. Such printing apparatusincludes an ink jet-type printing apparatus that uses ink obtained bymixing or dissolving a pigment or a dye with or in a solvent andtransfers ink droplets in the liquid state to implement printing, aprinting apparatus that uses an ink cartridge with an ink toneraccommodated therein, and a thermal transfer-type printing apparatus.

SUMMARY OF THE INVENTION

The object of the present invention is thus to provide a technique thatis applicable to a printer and an ink cartridge attached thereto andenables information relating to the ink cartridge, such as pieces ofinformation on remaining quantities of inks, to be adequately processed,while not increasing the manufacturing cost of the ink cartridge.

At least part of the above and the other related objects is actualizedby a first printer, to which an ink cartridge is detachably attached,wherein the ink cartridge keeps ink therein and has a rewritablenon-volatile memory. The first printer causes the ink kept in the inkcartridge to be transferred from a print head mounted on the printer toa printing medium, thereby implementing a printing operation. The firstprinter includes: a printer memory that stores information relating tothe ink kept in the ink cartridge into a predetermined area thereof in apredetermined format of addressing, which is different from a specificformat of addressing adopted in the non-volatile memory; a memorywriting unit that reads the information relating to the ink kept in theink cartridge from the predetermined area and writes the read-outinformation into a specific area of the non-volatile memory, whichcorresponds to the predetermined area of the printer memory; and anaddress decoder that converts a storage format of addressing of theinformation relating to the ink from the predetermined format ofaddressing into the specific format of addressing when the memorywriting unit writes the information.

The present invention is also directed to a first method thatcorresponds to the first printer discussed above. The present inventionthus provides a first method of writing information relating to ink keptin an ink cartridge into a rewritable non-volatile memory incorporatedin the ink cartridge, which is detachably attached to a printer, whereinthe printer causes the ink kept in the ink cartridge to be transferredfrom a print head mounted on the printer to a printing medium, therebyimplementing a printing operation. The first method includes the stepsof: storing the information relating to the ink kept in the inkcartridge into a predetermined area of a printer memory incorporated inthe printer in a predetermined format of addressing, which is differentfrom a specific format of addressing adopted in the non-volatile memory;reading the information relating to the ink kept in the ink cartridgefrom the predetermined area; converting a storage format of addressingof the information relating to the ink from the predetermined format ofaddressing into the specific format of addressing; and writing theinformation in the converted specific format of addressing into aspecific area of the non-volatile memory, which corresponds to thepredetermined area of the printer memory.

In the first printer and the corresponding first method of the presentinvention, the information relating to the ink kept in the ink cartridgeis stored in different formats of addressing in the printer memoryincorporated in the printer and in the non-volatile memory incorporatedin the ink cartridge. The address decoder converts the storage format ofaddressing when the information is written into the non-volatile memoryof the ink cartridge. This arrangement enables the information relatingto the ink to be readily written into the non-volatile memory of the inkcartridge, even when the format of addressing adopted in thenon-volatile memory is different from that adopted in the printermemory.

In the first printer of the present invention, in the case where the inkcartridge is detachably attached to a carriage that has the print headmounted thereon and moves forward and backward relative to the printingmedium, the address decoder may also be disposed on the carriage. Thisarrangement shortens the distance between the address decoder and theink cartridge. This is especially advantageous when there is adifficulty in extending the signal lines because of the specific formatof addressing adopted in the non-volatile memory of the ink cartridge.

The present invention is further directed to a first ink cartridge thatcorresponds to the first printer discussed above. The present inventionaccordingly provides a first ink cartridge that keeps ink therein and isdetachably attached to a printer with a print head, wherein the printercauses the ink kept in the ink cartridge to be transferred from theprint head to a printing medium by a unit of dot, thereby implementing aprinting operation. The first ink cartridge includes: a rewritablenon-volatile memory; an input unit that receives information relating toink kept in the ink cartridge, which has been stored in a predeterminedformat of addressing in a predetermined area of a printer memoryincorporated in the printer, in a specific format of addressing that isdifferent from the predetermined format of addressing; and a writingcontroller that writes the information into the non-volatile memory inthe specific format of addressing received by the input unit.

In the first ink cartridge of the present invention, the information,which has been stored in a predetermined format of addressing in apredetermined area of the printer memory incorporated in the printer, isreceived in a specific format of addressing that is different from thepredetermined format of addressing and written into the non-volatilememory. This means that the data are written into the non-volatilememory of the ink cartridge, irrespective of the format of addressingadopted in the printer memory. In a similar manner, the readingoperation of data may be carried out in the specific format ofaddressing that is different from the format of addressing adopted inthe printer memory.

In accordance with one preferable application of the present invention,the non-volatile memory of the ink cartridge carries out transmission ofdata by serial access, and the information is written into thenon-volatile memory synchronously with a clock for addressing. Thenon-volatile memory of the serial access type generally has a reducednumber of terminals and is small in size, thereby contributing to thesize reduction of the whole ink cartridge.

The information written into the non-volatile memory is, for example, apiece of information relating to the quantity of ink in the inkcartridge. The piece of information relating to the quantity of ink mayregard a remaining quantity of ink or an amount of ink consumption withrespect to the ink cartridge.

In accordance with another preferable application of the presentinvention, a plurality of different inks are kept in the ink cartridge,and the address decoder carries out the conversion of the storage formatof addressing corresponding to a plurality of areas provided for therespective inks in the non-volatile memory. In a color ink cartridgewith three different colors, for example, cyan, magenta, and yellow,kept therein, this arrangement facilitates the storage of informationwith regard to the respective color inks. The same principle isapplicable to another ink cartridge, in which at least five differentinks are kept. In these cases, the storage capacity of not greater than2 bytes is allocated to store a piece of information relating to thequantity of each ink. The allocation of the storage capacity ofapproximately 2 bytes to each ink enables the data to be written intothe non-volatile memory of the ink cartridge within a short time period.

In accordance with still another preferable application of the presentinvention, the non-volatile memory of the ink cartridge has twoinformation storage areas, in order to enhance the reliability of thestored information. In this structure, the address decoder alternatelyspecifies one of two different addresses every time a requirement ofwriting information, which has been stored in one area of the printermemory, into the non-volatile memory is output. This arrangement causesthe address decoder to specify the addresses and thereby reduces theloading to the printer main body.

The information may be written into the non-volatile memory of the inkcartridge after at least one of a timing when a power-off instruction isgiven to turn off a power source of the printer, a timing when powersupply to the printer is cut off, and a timing when a replacementinstruction is given to replace the ink cartridge. In this arrangement,the address decoder carries out the conversion of the storage format ofaddressing and writes the information having the converted format intothe non-volatile memory after at least one of the above timings. Writingthe information into the non-volatile memory of the ink cartridge at theabove timings enables the reliability of information to be kept at asufficient level. In the case where the ink cartridge is detached fromthe printer, this arrangement enables the latest data to be stored inthe non-volatile memory of the ink cartridge. A cleaning operation isgenerally carried out in an ink jet printer, in order to prevent nozzleson the print head from being clogged. The cleaning operation consumes apreset amount of ink. It is accordingly desirable to update theinformation relating to the quantity of ink after each cleaningoperation.

A programmable ROM that is erasable electrically, a flash ROM, or aferroelectric memory may be applied for the non-volatile memory of theink cartridge.

The present invention is also directed to a second printer, to which anink cartridge is detachably attached, wherein the ink cartridge keepsink therein and has a rewritable non-volatile memory. The second printercauses the ink kept in the ink cartridge to be transferred from aplurality of dot-forming elements, which are formed on a print headmounted on the printer, to a printing medium by a unit of dot, therebyimplementing a printing operation. The second printer includes: aprinter memory that stores information relating to the ink kept in theink cartridge into a predetermined area thereof; a data registrationunit that is disposed on a carriage, which has the print head mountedthereon and moves forward and backward relative to the printing medium,and temporarily registers therein the information relating to the ink,which is read from the predetermined area of the printer memory; and amemory writing unit that writes the information temporarily registeredin the data registration unit into a specific area of the non-volatilememory, which corresponds to the predetermined area of the printermemory.

The present invention is also directed to a second method thatcorresponds to the second printer discussed above. The present inventionthus provides a second method of writing information relating to inkkept in an ink cartridge into a rewritable non-volatile memoryincorporated in the ink cartridge, which is detachably attached to aprinter, wherein the printer causes the ink kept in the ink cartridge tobe transferred from a plurality of dot-forming elements, which areformed on a print head mounted on the printer, to a printing medium by aunit of dot, thereby implementing a printing operation. The secondmethod includes the steps of: storing the information relating to theink kept in the ink cartridge into a predetermined area of a printermemory incorporated in the printer; temporarily storing the informationrelating to the ink, which is read from the predetermined area of theprinter memory, into a temporary memory that is disposed on a carriage,which has the print head mounted thereon and moves forward and backwardrelative to the printing medium; and writing the information temporarilystored in the temporary memory into a specific area of the non-volatilememory, which corresponds to the predetermined area of the printermemory.

The present invention is further directed to a second ink cartridge thatcorresponds to the second printer discussed above. The present inventionaccordingly provides a second ink cartridge that keeps ink therein andis detachably attached to a carriage set on a printer, wherein theprinter has a plurality of dot-forming elements formed on a print headmounted on the carriage that moves forward and backward relative to aprinting medium. The printer causes the ink kept in the ink cartridge tobe transferred from the plurality of dot-forming elements on the printhead to the printing medium by a unit of dot, thereby implementing aprinting operation. The second ink cartridge includes: a rewritablenon-volatile memory; an input unit that receives information relating toink kept in the ink cartridge, which has been stored in a predeterminedformat of addressing in a temporary memory mounted on the carriage fortemporarily storing information, in a specific format of addressing thatis different from the predetermined format of addressing; and a writingcontroller that writes the information into the non-volatile memory inthe specific format of addressing received by the input unit.

In the second printer as well as the corresponding second method and thesecond ink cartridge of the present invention, the information relatingto the ink kept in the ink cartridge is stored in a predetermined areaof the printer memory. The information read from the predetermined areaof the printer memory is temporarily registered in the temporary memoryon the carriage and eventually written into the non-volatile memory ofthe ink cartridge. This arrangement does not require the time-consumingprocess of reading the respective pieces of information from the printermemory in response to each demand, but facilitates the writing operationof data into the non-volatile memory of the ink cartridge.

At least a partial area of a specific memory, in which datacorresponding to a driving signal to the dot-forming elements formed onthe print head are temporarily stored, may be utilized as the temporarymemory. The print head mounted on the carriage may have such a memory,in which data corresponding to a driving signal to the dot-formingelements are temporarily stored. This simplifies the configuration ofthe storage process.

The information read from the printer memory may be registered into thetemporary memory by utilizing the signal line, through which datacorresponding to a driving signal to the dot-forming elements are outputto the dot-forming elements. This simplifies the configuration of thestorage process.

A common hardware configuration may be applicable for output of data tothe dot-forming elements and for output of information to thenon-volatile memory. In this case, one desirable structure has amechanism of selecting either one of the output of data to thedot-forming elements and the output of information to the non-volatilememory. One concrete example of such structure cuts off the power supplyto the non-volatile memory in the case of the output of datacorresponding to a driving signal to the dot-forming elements.

In any one of the above applications, the information relating to thequantity of ink may regard a remaining quantity of ink or an amount ofink consumption with respect to the ink cartridge. The non-volatilememory may be a memory that carries out transmission of data by serialaccess, for example, a programmable ROM that is erasable electrically, aflash ROM, or a ferroelectric memory.

The structure of incorporating the non-volatile memory in the inkcartridge is applicable to any type of the ink cartridge. For example,in the case where both a black ink cartridge, in which black ink iskept, and a color ink cartridge, in which a plurality of different colorinks are kept, are detachably attached to the printer, the non-volatilememory is provided in both the black ink cartridge and the color inkcartridge, and required pieces of information are written into therespective non-volatile memories. The configuration that provides anon-volatile memory for each ink cartridge enables the data on thequantity of ink with regard to each ink cartridge to be processedindependently. The principle of the present invention is also applicableto a printer, to which only a black ink cartridge or a color inkcartridge is detachably attached.

These and other objects, features, aspects, and advantages of thepresent invention will become more apparent from the following detaileddescription of the preferred embodiment with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating the structure of a main partof a printer 1 in one embodiment according to the present invention;

FIGS. 2A and 2B are perspective views respectively illustrating thestructures of an ink cartridge 107K and a cartridge attachment unit 18in the embodiment;

FIG. 3 is a sectional view illustrating an attachment state in which theink cartridge 107K shown in FIG. 2A is attached to the cartridgeattachment unit 18 shown in FIG. 2B;

FIG. 4 is a block diagram illustrating the internal structure of theprinter 1 of the embodiment including a print controller 40;

FIG. 5 is a block diagram showing connections of a control IC 200 in theembodiment;

FIG. 6 is a block diagram showing an internal structure of a drivingcircuit 230 of a print head 10 in the embodiment;

FIG. 7 shows a layout of nozzle openings 23 formed on the print head 10in the embodiment;

FIG. 8 is a block diagram showing the structure of a storage element 80incorporated in black and color ink cartridges 107K and 107F;

FIG. 9A is a flowchart showing a processing routine to write data intothe storage element 80;

FIG. 9B is a timing chart showing the timing of execution of theprocessing shown in the flowchart of FIG. 9A;

FIG. 10 shows a data array in the storage element 80 incorporated in theblack ink cartridge 107K attached to the printer 1 in the embodiment;

FIG. 11 shows a data array in the storage element 80 incorporated in thecolor ink cartridge 107F attached to the printer 1 in the embodiment;

FIG. 12 shows a data array in an EEPROM 90 incorporated in the printcontroller 40 of the printer 1 in the embodiment;

FIG. 13 is a flowchart showing a processing routine executed at a timeof power supply to the printer 1;

FIG. 14 is a flowchart showing a processing routine executed tocalculate the remaining quantities of inks;

FIG. 15 is a flowchart showing a processing routine executed byinterruption in response to a requirement of power-off ;

FIG. 16 shows a color ink cartridge 500 having an exposed storageelement as one modification of the embodiment;

FIG. 17 shows a structure without a transfer controller 220 as anothermodification of the embodiment; and

FIG. 18 shows another structure as still another modification of theembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(Mechanical Structure of Printer 1)

FIG. 1 is a perspective view illustrating the structure of a main partof an ink jet printer 1 in one embodiment according to the presentinvention. The printer 1 of the embodiment is used in connection with acomputer PC, to which a scanner SC is also connected. The computer PCreads and executes an operating system and predetermined programs tofunction, in combination with the printer 1, as a printing apparatus.The computer PC executes an application program on a specific operatingsystem, carries out processing of an input image, for example, read fromthe scanner SC, and displays a processed image on a CRT display MT. Whenthe user gives a printing instruction after the required imageprocessing, for example, retouching the image on the CRT display MT, isconcluded, a printer driver incorporated in the operating system isactivated to transfer processed image data to the printer 1. A CD drive(not shown) that reads a recording medium, such as a CD-ROM, and othernon-illustrated drives are mounted on the computer PC.

The printer driver converts original color image data, which are inputfrom the scanner SC and subjected to the required image processing, tocolor image data printable by the printer 1 in response to the printinginstruction, and outputs the converted color image data to the printer1. The original color image data consists of three color components,that is, red (R), green (G), and blue (B). The converted color imagedata printable by and output to the printer 1 consists of six colorcomponents, that is, black (K), cyan (C), light cyan (LC), magenta (M),light magenta (LM), and yellow (Y). The printable color image data arefurther subjected to binary processing, which specifies the on-off stateof ink dots. These image processing and data conversion processes areknown in the art and are thus not specifically described here. Theseprocesses may be carried out in the printer 1, in place of the printerdriver included in the computer PC, as discussed later.

The following describes the basic structure of the printer 1. Referringto FIG. 1, the printer 1 has a print controller 40 that is in charge ofcontrol procedures and a print engine 5 that actually performs ejectionof ink. The print controller 40 and the print engine 5 are incorporatedin a printer main body 100. The print engine 5 included in the printermain body 100 has a print head 10, a sheet feed mechanism 11, and acarriage mechanism 12. The print head 10 is integrally formed with acartridge attachment unit 18 to construct a carriage 101. The print head10, which is an ink jet type, is mounted on a specific face of thecarriage 101 that faces a sheet of printing paper 105, that is, a lowerface of the carriage 101 in this embodiment. Transfer of print data tothe print head 10 is carried out via a flexible flat cable (FFC) 300.The carriage mechanism 12 includes a carriage motor 103 and a timingbelt 102. The carriage motor 103 drives the carriage 101 via the timingbelt 102. The carriage 101 is guided by a guide member 104 and movesforward and backward along a width of the printing paper 105 by means ofnormal and reverse rotations of the carriage motor 103. The sheet feedmechanism 11 that feeds the printing paper 105 includes a sheet feedroller 106 and a sheet feed motor 116.

A black ink cartridge 107K and a color ink cartridge 107F, which will bedescribed later, are detachably attached to the cartridge attachmentunit 18 of the carriage 101. The print head 10 receives supplies of inksfed from these ink cartridges 107K and 107F and ejects ink dropletsagainst the printing paper 105 with a movement of the carriage 101, soas to create dots and print a picture image or letters on the printingpaper 105.

Each of the ink cartridges 107K and 107F has a cavity therein forkeeping ink, which is prepared by dissolving or dispersing a dye or apigment in a solvent. The cavity for keeping ink therein is generallyreferred to as an ink chamber. The black ink cartridge 107K has an inkchamber 117K, in which black ink (K) is kept. The color ink cartridge107F has a plurality of ink chambers 107C, 107LC, 107M, 107LM, and 107Y,which are formed separately. Cyan ink (C), light cyan ink (LC), magentaink (M), light magenta ink (LM), and yellow ink (Y) are keptrespectively in these ink chambers 107C, 107LC, 107M, 107LM, and 107Y.The print head 10 receives supplies of various color inks fed from therespective ink chambers 107C, 107LC, 107M, 107LM, and 107Y, and ejectsink droplets of various colors to implement color printing.

A capping unit 108 and a wiping unit 109 are disposed on one end of theprinter 1, which is included in a non-printable area. The capping unit108 closes nozzle opening formed on the print head 10 during thestoppage of printing operation. The capping unit 108 effectivelyprevents the solvent component in the ink from being vaporized duringthe stoppage of printing operation. Preventing the vaporization of thesolvent component in the ink favorably depresses an increase inviscosity of ink and formation of an ink film. Capping the nozzleopenings during the stoppage of printing operation effectively preventsthe nozzles from being clogged. The capping unit 108 also has a functionof collecting ink droplets ejected from the print head 10 by a flushingoperation. The flushing process is carried out to eject ink when thecarriage 101 reaches the end of the printer 1 during the execution ofthe printing operation. The flushing process is one of the actions forpreventing the nozzles from being clogged. The wiping unit 109 islocated in the vicinity of the capping unit 108 to wipe the surface ofthe print head 10, for example, with a blade, so as to wipe out the inkresidue or paper dust adhering to the surface of the print head 10. Inaddition to these actions, the printer 1 of the embodiment carries out asucking operation with regard to the nozzles, for example, in the caseof abnormality occurring due to invasion of bubbles into the nozzles.The sucking process presses the capping unit 108 against the print head10 to seal the nozzle openings, activates a suction pump (not shown),and makes a passage connecting with the capping unit 108 in a negativepressure, so as to cause ink to be sucked out of the nozzles on theprint head 10. The flushing operation, the wiping operation, and thesucking operation are included in a head cleaning procedure. The wipingoperation may be carried out by an automatic mechanism that uses apreset blade and automatically wipes the surface of the print head 10with forward and backward movements of the carriage 101. In this case,only the flushing operation and the sucking operation are included inthe active head cleaning procedure.

(Structure of Ink Cartridges 107K, 107F and Cartridge Attachment Unit18)

The following describes the attachment of the ink cartridges 107K and107F to the ink jet printer 1. The black ink cartridge 107K and thecolor ink cartridge 107F have a common basic structure. The followingdescription accordingly regards the structure of the ink cartridge, theblack ink cartridge 107K as an example, and the structure of thecartridge attachment unit 18 of the printer main body 100, whichreceives and holds the ink cartridge 107K attached thereto, withreference to FIGS. 2A, 2B, and 3.

FIGS. 2A and 2B are perspective views schematically illustrating thestructures of the ink cartridge 107K and the cartridge attachment unit18 of the printer main body 100. FIG. 3 is a sectional view illustratingan attachment state in which the ink cartridge 107K is attached to thecartridge attachment unit 18.

Referring to FIG. 2A, the ink cartridge 107K has a cartridge main body171 that is composed of a synthetic resin and defines the ink chamber117K in which black ink is kept, and a storage element (non-volatilememory) 80 incorporated in a side frame 172 of the cartridge main body171. An EEPROM is generally applied for the storage element 80 that isrewritable by electrically erasing the non-required contents of storageand maintains the contents of storage even after the power supply is cutoff. The allowable frequency of rewriting data in the storage element 80is about ten thousand times, which is significantly lower than theallowable frequency of rewriting in an EEPROM 90 (described later)incorporated in the print controller 40. This makes the cost of thestorage element 80 extremely low. The storage element 80 enablestransmission of various data to and from the print controller 40 of theprinter 1, while the ink cartridge 107K is attached to the cartridgeattachment unit 18 of the printer main body 100 shown in FIG. 2B. Thestorage element 80 is received in a bottom-opened recess 173 formed inthe side frame 172 of the ink cartridge 107K. The storage element 80 hasa plurality of connection terminals 174 exposed to the outside in thisembodiment. The whole storage element 80 may, however, be exposed to theoutside. Alternatively the whole storage element 80 is embedded, andseparate connection terminals may be provided independently.

Referring to FIG. 2B, the cartridge attachment unit 18 has an ink supplyneedle 181, which is disposed upward on a bottom 187 of a cavity, inwhich the ink cartridge 107K is accommodated. A recess 183 is formedabout the needle 181. When the ink cartridge 107K is attached to thecartridge attachment unit 18, an ink supply unit 175 (see FIG. 3), whichis projected from the bottom of the ink cartridge 107K, is fitted in therecess 183. Three cartridge guides 182 are set on the inner wall of therecess 183. A connector 186 is placed on an inner wall 184 of thecartridge attachment unit 18. The connector 186 has a plurality ofelectrodes 185, which are in contact with and thereby electricallyconnect with the plurality of connection terminals 174 of the storageelement 80 included in the ink cartridge 107K that is set in thecartridge attachment unit 18.

The connector 186 is arranged to pass through the inner wall 184 and hasa contact pin that is disposed on the opposite side of the electrodes185 and is in contact with a control board 205 mounted on the carriage101 as shown in the sectional view of FIG. 3. When the control board 205is attached to an outer fixation element 250 of the cartridge attachmentunit 18, the control board 205 electrically connects with the storageelement 80 via the connector 186. The connector 186 functions as asignal path, through which signals are transmitted between the storageelement 80 and the control board 205. The control board 205 is connectedto a parallel input-output interface 49 of the print controller 40(described later) via the FFC 300.

The following describes the detailed structure of the print controller40 included in the printer 1, as well as data transmission between theprint controller 40 and the print head 10 mounted on the carriage 101and between the print controller 40 and the storage elements 80incorporated in the black and color ink cartridges 107K and 107F. FIG. 4is a functional block diagram illustrating the ink jet printer 1 of thisembodiment. The print controller 40 has an interface 43 that receivesvarious data, such as print data, transmitted from the computer PC, aRAM 44 in which the various data including print data are stored, and aROM 45 in which programs for various data processing are stored. Theprint controller 40 further has a controller 46 including a CPU, anoscillator circuit 47, a driving signal generator circuit 48 thatgenerates a driving signal COM given to the print head 10, and theparallel input-output interface 49 that transmits the print datadeveloped to dot pattern data and the driving signal COM to the printengine 5.

Control lines of a switch panel 92 and a power source 91 are alsoconnected to the print controller 40 via the parallel input-outputinterface 49. The switch pane 192 has a power switch 92a for turning thepower source 91 on and off, a cartridge switch 92b for giving aninstruction to replace the ink cartridge currently attached to theprinter 1 with another ink cartridge, and a cleaning switch 92c forgiving an instruction to perform the forcible cleaning of the print head10. When the power switch 92a on the switch panel 92 is operated toinput an instruction of a power-off operation, a requirement ofnon-maskable interruption NMI is generated. The print controller 40immediately shifts to a predetermined interruption process and outputs apower down instruction to the peripheral circuit including the powersource 91, in response to the requirement of non-maskable interruptionNMI. The power source 91 receives the power down instruction and fallsinto a stand-by state. In the stand-by state, the power source 91supplies a stand-by electric power to the print controller 40 via apower supply line (not shown), while stopping the main power supply. Thestandard power-off operation carried out via the switch panel 92 thusdoes not completely cut off the power supply to the print controller 40.

The requirement of non-maskable interruption NMI is also output when thecartridge switch 92b on the switch panel 92 is operated to give aninstruction of replacing the ink cartridge, and when the power plug ispulled out of the socket. In response to the output of the requirementof non-maskable interruption NMI, the print controller 40 executes aninterruptive processing routine discussed later. In the interruptiveprocessing routine, the case of an output of the requirement ofinterruption NMI due to an operation of a switch on the switch panel 92is distinguishable from the case of an output of the requirement ofinterruption NMI due to the forcible cut-off of the power supply.Different processes may thus be carried out according to the cause ofthe output of the requirement of interruption NMI, as discussed later.The power source 91 has an auxiliary power unit, for example, acapacitor, to ensure a power supply for a predetermined time period, forexample, 0.3 seconds, after the power plug is pulled out of the socket.

The print controller 40 has the EEPROM 90 mounted thereon as a memory ofthe printer main body 100, which stores information relating to theblack ink cartridge 107K and the color ink cartridge 107F mounted on thecarriage 101 as shown in FIG. 1. The EEPROM 90 stores plural pieces ofspecific information including information relating to quantities ofinks in the black ink cartridge 107K and the color ink cartridge 107F,as discussed later in detail. The ink quantity-relating information mayregard the remaining quantities of the respective inks in the inkcartridges 107K and 107F or the amounts of consumption of the respectiveinks with regard to the ink cartridges 107K and 107F.

(Connection Between Print Controller 40 and Carriage 101)

The FFC 300 that connects the parallel input-output interface 49 of theprint controller 40 with the carriage 101 has five signal lines. Namelydata are transferred through only these five signal lines from the printcontroller 40 to the print head 10 mounted on the carriage 101 and tothe storage elements 80 incorporated in the ink cartridges 107K and 107Fset on the carriage 101.

The control board 205 is connected with the print controller 40 via theFFC 300. A transfer controller 220, a control IC 200, and a RAM 210 aremounted on the control board 205. FIG. 5 shows the detailed structure ofthe control board 205 on the carriage 101 and the peripheral elements.As shown in FIG. 5, the transfer controller 220 on the control board 205controls data transmission between the control IC 200 and the printcontroller 40 and output of data from the print controller 40 to adriving circuit 230, using four signals SG1 through SG4 and a selectioncontrol signal SSL received via the FFC 300.

Namely the transfer controller 220 selects either the control IC 200 orthe driving circuit 230 as the destination of data transmission from andto the parallel input-output interface 49 of the print controller 40 viathe FFC 300. The four signals SG1 through SG4 connecting with theparallel input-output interface 49 are output to the driving circuit 230as the driving signal COM, a latch signal LAT, a clock signal CLK, andrecording data S1, in the case where the selection control signal SSL isat the high level. In the case where the selection control signal SSL isat the low level, on the other hand, the four signals SG1 through SG4are connected with the control IC 200 as a receiving signal R×D, atransmitting signal T×D, a power down signal NMI, and a selection signalSEL.

When the selection control signal SSL is at the high level, the printcontroller 40 enables signals for generating an image to be output fromthe parallel input-output interface 49 to the driving circuit 230 viathe transfer controller 220. The print controller 40 causes ink dropletsto be ejected from the respective nozzles on the print head 10, so as toimplement printing, while driving the sheet feed mechanism 11 and thecarriage mechanism 12 of the print engine 5. This process is describedmore in detail.

Referring back to FIG. 4, the driving circuit 230 includes a shiftregister circuit 13 that converts serially transferred data to paralleldata corresponding to the respective nozzles, a latch circuit 14 thatholds the output of the shift register circuit 13 for a predeterminedtime period, a level shifter circuit 15 that amplifies the output of thelatch circuit 14 to a voltage level of several tens volts, and a nozzleselection circuit (analog switch) 16 that is operated in response to theoutput of the level shifter circuit 15. The driving signal COM outputfrom the driving signal generator circuit 48 connects with the input ofthe nozzle selection circuit 16. The output of the nozzle selectioncircuit 16 connects with a plurality of piezoelectric vibrators 17provided on the print head 10, in order to control ejection of ink fromcorresponding nozzle openings 23 formed on the lower part of the printhead 10. The shift register circuit 13, the latch circuit 14, the levelshifter circuit 15, and the nozzle selection circuit 16 respectivelyinclude a plurality of elements corresponding to the number ofpiezoelectric vibrators 17 mounted on the print head 10. This is shownin FIG. 6. There are a large number of nozzle openings 23 set for eachink on the print head 10 as shown in FIG. 7, and one piezoelectricvibrator 17 is allocated to each nozzle opening 23. The print head 10has a plurality of nozzle arrays respectively corresponding to the blackink (K), the cyan ink (C), the light cyan ink (LC), the magenta ink (M),the light magenta ink (LM), and the yellow ink (Y). Each nozzle arrayincludes the nozzle openings 23 arranged in two lines and zigzag.

As shown in FIG. 6, the shift register circuit 13 includes shiftregisters 13A through 13N, the latch circuit 14 includes latches 14Athrough 14N, the level shifter circuit 15 includes level shifters 15Athrough 15N, and the nozzle selection circuit 16 includes switchingelements 16A through 16N, all corresponding to piezoelectric vibrators17A through 17N allocated to the respective nozzle openings 23. Thedriving circuit 230 receives the recording data S1 output from the printcontroller 40. The recording data S1 has either a value ‘1’ or a value‘0’ that represents whether or not an ink droplet should be ejected fromeach nozzle opening 23. The driving circuit 230 successively transfersthe recording data S1 to the shift registers 13A through 13Nsynchronously with the clock signal CLK. When the recording data S1 ofone recording cycle with regard to all the nozzle openings 23 aretransferred, bit data of either ‘1’ or ‘0’ are set in all the shiftregisters 13A through 13N. In response to the output of the latch signalLAT in this state, the bit data set in the respective shift registers13A through 13N are transferred to the respective latches 14A through14N. The shift register circuit 13 and the latch circuit 14 arecollectively referred to as a data holding circuit 130.

While the respective latches 14A through 14N included in the latchcircuit 14 hold data, the shift register circuit 13 receives a next setof transferred recording data S1 of a subsequent recording cycle. Theoutput voltages of the latch circuit 14 are converted by the respectivelevel shifters 15A through 15N of the level shifter circuit 15 andoutput to the respective switching elements 16A through 16N.

In the case where the outputs of the level shifters 15A through 15N areat the high level (that is, the bit data ‘1’), the respective switchingelements 16A through 16N of the nozzle selection circuit 16 constructedas the analog switch are set in the ‘ON’ position. The switchingelements 16A through 16N corresponding to the level shifters 15A through15N having the outputs of the level data ‘1’ cause the driving signalCOM, which is output at a specific timing, to be transmitted to thecorresponding piezoelectric vibrators 17A through 17N. The piezoelectricvibrators 17A through 17N receiving the driving signal COM are displacedaccording to the waveform of the driving signal COM. Each pressurechamber 32 on the print head 10 is then compressed to apply a pressureto the ink in the pressure chamber 32, so as to cause an ink droplet tobe ejected from the corresponding nozzle opening 23.

In the case where the outputs of the level shifters 15A through 15N areat the low level (that is, the bit data ‘0’), the respective switchingelements 16A through 16N are set in the ‘OFF’ position. This cuts offthe transmission of the driving signal COM to the respectivepiezoelectric vibrators 17A through 17N, which accordingly keep theprevious electric charges. No ink droplet is thus ejected from thecorresponding nozzle opening 23.

When the selection control signal SSL output from the parallelinput-output interface 49 is at the lower level, on the other hand, thefour signal lines connect the parallel input-output interface 49 of theprint controller 40 with the control IC 200 via the transfer controller220. The print controller 40 thus carries out data transmission to andfrom the control IC 200 by serial communication. The four signal linesbetween the parallel input-output interface 49 and the control IC 200include the receiving signal line R×D, through which the control IC 200receives data, the transmitting signal line T×D, through which thecontrol IC 200 outputs data, the power down signal line NMI, throughwhich the print controller 40 outputs a requirement of writing operationat the time of power failure to the control IC 200, and the selectionsignal line SEL that allows transmission of data through either thesignal line R×D or the signal line T×D. The controller 46 transmitsrequired data to and from the control IC 200 using these four signals.The speed of communication between the controller 46 and the control IC200 is sufficiently higher than the speed of data transmission betweenthe control IC 200 and the storage elements 80. The power down signalNMI is output when the power switch 92 a on the switch panel 92 isoperated, when the cartridge switch 92 b on the switch panel 92 isoperated, and when the power supply is forcibly cut off by pulling thepower plug out of the socket.

In response to the selection control signal SSL at the low level, theprint controller 40 connects with the control IC 200 via the transfercontroller 230 by serial communication and transfers informationrelating to the ink cartridges 107K and 107F, for example, informationon the quantities of inks in the ink cartridges 107K and 107F, to thecontrol IC 200. The control IC 200 temporarily registers the inputinformation in the RAM 210 and writes the information into therespective storage elements 80 of the ink cartridges 107K and 107F at apredetermined timing, for example, at the timing of an output of thepower down signal NMI.

The control IC 200 has a function of separately transmitting data to andfrom the two storage elements 80 mounted on the ink cartridges 107K and107F as shown in FIG. 5. Namely one control IC 200 attains datatransmission to and from the respective storage elements 80 of the blackink cartridge 107K and the color ink cartridge 107F. In the illustrationof FIG. 5, in order to discriminate the signal lines to the respectivestorage elements 80, a suffix ‘1’ is added to a power source line Powerand respective signals CS, W/R, DATA, and CLK with regard to the blackink cartridge 107K and a suffix ‘2’ is added with regard to the colorink cartridge 107F.

In the embodiment of the above arrangement, the writing operation ofdata into the storage elements 80 of the ink cartridges 107K and 107F iscarried out with the power down signal NMI output, for example, inresponse to an operation of the power switch 92 a on the switch panel92. The writing operation of data into the storage elements 80 mayalternatively be carried out with a command output through the receivingsignal line R×D. In the latter case, the required number of signal linesbetween the transfer controller 220 and the control IC 200 may bereduced to three. The driving signal COM among the signal lines outputto the driving circuit 230 may be output directly from the parallelinput-output interface 49 to the driving circuit 230. In this modifiedarrangement, both the signal lines between the transfer controller 220and the control IC 200 and the signal lines between the transfercontroller 220 and the driving circuit 230 may be reduced in number tothree. This enables the signal line SG4 connecting with the transfercontroller 220 via the FFC 300 to be omitted.

(Structure of Storage Elements 80)

FIG. 8 is a block diagram showing the configuration of the storageelements 80 incorporated in the ink cartridges 107K and 107F attached tothe ink jet printer 1 of the embodiment. The storage element 80 of theink cartridges 107K and 107F includes a memory cell 81, a write/readcontroller 82, and an address counter 83. The write/read controller 82is a circuit that controls writing and reading operations of data intoand from the memory cell 81. The address counter 83 counts up inresponse to the clock signal CLK and generates an output that representsan address with regard to the memory cell 81.

The actual procedure of writing operation is described with reference toFIGS. 9A and 9B. FIG. 9A is a flowchart showing a processing routineexecuted by the print controller 40 in the printer 1 of the embodimentto write the remaining quantities of inks into the storage elements 80incorporated in the black and color ink cartridges 107K and 107F, andFIG. 9B is a timing chart showing the timing of execution of theprocessing shown in the flowchart of FIG. 9A.

The controller 46 of the print controller 40 first makes a chip selectsignal CS, which sets the storage element 80 in an enabling state, in ahigh level at step ST21. While the chip select signal CS is kept at thelow level, the count on the address counter 83 is set equal to zero.When the chip select signal CS is set to the high level, the addresscounter 83 is enabled to start the count. The controller 46 thengenerates a required number of pulses of the clock signal CLK to specifyan address, at which data are written, at step ST22. The control IC 200determines the required number of pulses of the clock signal CLK. Inthis meaning, the control IC 200 functions as an address decoder thatconverts the format of addressing in the EEPROM 90 into the format ofaddressing in the storage elements 80. The address counter 83 includedin the storage element 80 counts up in response to the required numberof pulses of the clock signal CLK thus generated. During this process, awrite/read signal W/R is kept in a low level. This means that aninstruction of reading data is given to the memory cell 81. Dummy dataare accordingly read synchronously with the output clock signal CLK.

After the address counter 83 counts up to the specified address forwriting data, the controller 46 carries out an actual writing operationat step ST23. The writing operation switches the write/read signal W/Rto the high level, outputs one-bit data to a data terminal I/O, andchanges the clock signal CLK to a high active state on the completion ofdata output. While the write/read signal W/R is in the high level, dataDATA of the data terminal I/O are written into the memory cell 81 of thestorage element 80 synchronously with a rise of the clock signal CLK.Although the writing operation starts synchronously with a fifth pulseof the clock signal CLK in the example of FIG. 9B, this only describesthe general writing procedure. The writing operation of required data,for example, the remaining quantity of ink, may be carried out at anypulse, for example, at a first pulse, of the clock signal CLK accordingto the requirements.

Data arrays of the storage elements 80, in which data are written, aredescribed with reference to FIGS. 10 and 11. FIG. 10 shows a data arrayin the storage element 80 incorporated in the black ink cartridge 107Kattached to the printer 1 of this embodiment shown in FIG. 1. FIG. 11shows a data array in the storage element 80 incorporated in the colorink cartridge 107F attached to the printer 1. FIG. 12 shows a data arrayin the EEPROM 90 incorporated in the print controller 40 of the printermain body 100.

Referring to FIG. 10, the memory cell 81 of the storage element 80incorporated in the black ink cartridge 107K has a first storage area750, in which read only data are stored, and a second storage area 760,in which rewritable data are stored. The printer main body 100 can onlyread the data stored in the first storage area 750, while performingboth the reading and writing operations with regard to the data storedin the second storage area 760. The second storage area 760 is locatedat a specific address, which is accessed prior to the first storage area750 in the state without no specific processing, that is, in the case ofdefault. Namely the second storage area 760 has a lower address thanthat of the first storage area 750. In the specification hereof, theexpression ‘lower address’ means an address closer to the head of thememory space.

In the second storage area 760, data regarding the frequency ofattachment of the ink cartridge is registered in a head portion 700thereof. First data on the remaining quantity of black ink and seconddata on the remaining quantity of black ink are respectively allocatedto first and second black ink remaining quantity memory divisions 701and 702, which follow the head portion 700 and are accessed in thisorder.

There are the two black ink remaining quantity memory divisions 701 and702 for storing the data on the remaining quantity of black ink. Thisarrangement enables the data on the remaining quantity of black ink tobe written alternately in these two memory divisions 701 and 702. If thelatest data on the remaining quantity of black ink is stored in thefirst black ink remaining quantity memory division 701, the data on theremaining quantity of black ink stored in the second black ink remainingquantity memory division 702 is the previous data immediately before thelatest data, and the next writing operation is performed in the secondblack ink remaining quantity memory division 702.

Both the first and second black ink remaining quantity memory divisions701 and 702 have a storage capacity of 1 byte or 8 bits. Anotherpreferable application allocates the data on the remaining quantity ofblack ink to a certain address that is accessed prior to the data on thefrequency of attachment of the ink cartridge in the storage element 80of the black ink cartridge 107K. This arrangement enables the data onthe remaining quantity of black ink to be accessed first, for example,in the case of a power-off time discussed later.

The read only data stored in the first storage area 750 include data onthe time (year) of unsealing the ink cartridge 107K, data on the time(month) of unsealing the ink cartridge 107K, version data of the inkcartridge 107K, data on the type of ink, for example, a pigment or adye, data on the year of manufacture of the ink cartridge 107K, data onthe month of manufacture of the ink cartridge 107K, data on the date ofmanufacture of the ink cartridge 107K, data on the production line ofthe ink cartridge 107K, serial number data of the ink cartridge 107K,and data on the recycle showing whether the ink cartridge 107K isbrand-new or recycled, which are respectively allocated to memorydivisions 711 through 720 that are accessed in this order.

An intrinsic value is set to the serial number of each ink cartridge107K, which is accordingly utilized as ID (identification) information.In the case where the data on the year of manufacture, the month ofmanufacture, the date of manufacture, and the time of manufacturerepresent the precise time when a certain ink cartridge 107K has beenmanufactured (for example, to the unit of second or even 0.1 second),such data may be utilized as ID information.

Referring to FIG. 11, the memory cell 81 of the storage element 80incorporated in the color ink cartridge 107F has a first storage area650, in which read only data are stored, and a second storage area 660,in which rewritable data are stored. The printer main body 100 can onlyread the data stored in the first storage area 650, while performingboth the reading and writing operations with regard to the data storedin the second storage area 660. The second storage area 660 is locatedat a specific address that is accessed prior to the first storage area650. Namely the second storage area 660 has a lower address (that is, anaddress closer to the head) than that of the first storage area 650.

In the second storage area 660, data regarding the frequency ofattachment of the ink cartridge is registered in a head portion 600thereof. First data on the remaining quantity of cyan ink, second dataon the remaining quantity of cyan ink, first data on the remainingquantity of magenta ink, second data on the remaining quantity ofmagenta ink, first data on the remaining quantity of yellow ink, seconddata on the remaining quantity of yellow ink, first data on theremaining quantity of light cyan ink, second data on the remainingquantity of light cyan ink, first data on the remaining quantity oflight magenta ink, and second data on the remaining quantity of lightmagenta ink are respectively allocated to color ink remaining quantitymemory divisions 601 through 610, which follow the head portion 600 andare accessed in this order.

In the same manner as the black ink cartridge 107K, there are the twomemory divisions, that is, the first color ink remaining quantity memorydivision 601 (603, 605, 607, 609) and the second color ink remainingquantity memory division 602 (604, 606, 608, 610), for storing the dataon the remaining quantity of each color ink. This arrangement enablesthe data on the remaining quantity of each color ink to be rewrittenalternately in these two memory divisions.

Like the black ink cartridge 107K, both the first and second color inkremaining quantity memory divisions with regard to each color ink in thecolor ink cartridge 107F have a storage capacity of 1 byte or 8 bits. Asdiscussed above with regard to the storage element 80 of the black inkcartridge 107K, another preferable application allocates the data on theremaining quantities of respective color inks to certain addresses thatare accessed prior to the data on the frequency of attachment of the inkcartridge in the storage element 80 of the color ink cartridge 107F.This arrangement enables the data on the remaining quantities ofrespective color inks to be accessed first, for example, in the case ofa power-off time discussed later.

Like the black ink cartridge 107K, the read only data stored in thefirst storage area 650 include data on the time (year) of unsealing theink cartridge 107F, data on the time (month) of unsealing the inkcartridge 107F, version data of the ink cartridge 107F, data on the typeof ink, data on the year of manufacture of the ink cartridge 107F, dataon the month of manufacture of the ink cartridge 107F, data on the dateof manufacture of the ink cartridge 107F, data on the production line,serial number data, and data on the recycle that are respectivelyallocated to memory divisions 611 through 620, which are accessed inthis order. These data are common to all the color inks, so that onlyone set of data are provided and stored as common data to all the colorinks. As discussed above with regard to the black ink cartridge 107K,the serial number data may be usable as the ID information.

When the power source 91 of the printer 1 is turned on after the inkcartridges 107K and 107F are attached to the printer main body 100,these data are accessed and utilized by the print controller 40, and maybe stored into the EEPROM 90 incorporated in the printer main body 100as occasions demand. As shown in FIG. 12, memory divisions 801 through835 in the EEPROM 90 store all the data stored in the respective storageelements 80 including the remaining quantities of the respective inks inthe black ink cartridge 107K and the color ink cartridge 107F.

The EEPROM 90 has a plurality of memory divisions, in which the data onthe remaining quantity of black ink, the other data relating to theblack ink cartridge 107K, the data on the remaining quantities ofrespective color inks, and the other data relating to the color inkcartridge 107F are stored, as shown in FIG. 12. These data correspond tothose stored in the respective storage elements 80 of the black inkcartridge 107K and the color ink cartridge 107F. The difference is thatthe data on the remaining quantity of each ink has a data length of 32bits or 4 bytes in the EEPROM 90.

(Processing With Regard to Remaining Quantities of Inks Executed inPrinter 1)

The printer 1 of the embodiment determines the amount of ink consumptionby calculation. The calculation of the amount of ink consumption may becarried out by the printer driver incorporated in the computer PC or bythe printer 1. The calculation of the amount of ink consumption isperformed by taking into account the following two factors:

(1) Amount of ink consumption by printing an image:

In order to accurately calculate the amount of ink consumption in theprocess of printing, image data are subjected to color conversion andbinarization processes and converted to on-off data of ink dots. Withregard to the image data in the on condition of ink dots, the weight ofeach dot is multiplied with the number of dots. Namely the frequency ofejection of ink droplets from the nozzle openings 23 is multiplied bythe weight of each ink droplet. The amount of ink consumption may beapproximated from the densities of the respective pixels included in theimage data.

(2) Amount of ink consumption by cleaning the print head 10:

The amount of ink consumption by cleaning the print head 10 includes anamount of ink ejection by the flushing operation and an amount of inksuction by the sucking operation. The action of the flushing operationis identical with the normal ejection of ink droplets, and the amount ofink ejection by the flushing operation is thus calculated in the samemanner as described in the factor (1). The amount of ink consumption bythe sucking operation is stored in advance according to the revolvingspeed and the activation time of the sucking pump. The amount of inkconsumed by one sucking action is generally measured and stored inadvance.

The current remaining quantity of ink is determined by subtracting thecalculated amount of ink consumption from the previous remainingquantity of ink prior to the current printing operation. The controller46 carries out the calculation of the remaining quantity of inkaccording to a specific program, for example, one stored in the ROM 45,using data stored in the EEPROM 90.

In the arrangement of this embodiment, the color conversion andbinarization processes are performed by the printer driver in thecomputer PC as described previously. The printer 1 thus receives thebinary data, that is, the data on the dot on-off conditions with regardto each ink. The printer 1 multiplies the weight of ink for each dot(that is, the weight of each ink droplet) by the number of dots todetermine the amount of ink consumption, based on the input binary data.

The ink jet printer 1 of the embodiment receives the binary data asdescribed previously. The array of the binary data is, however, notcoincident with the nozzle array on the print head 10. The controller 46accordingly divides the RAM 44 into three portions, that is, an inputbuffer 44A, an intermediate buffer 44B, and an output buffer 44C (seeFIG. 4), in order to perform the rearrangement of the dot data array.The ink jet printer 1 may alternatively carry out the requiredprocessing for the color conversion and the binarization. In this case,the ink jet printer 1 registers the print data, which include themulti-tone information and are transmitted from the computer PC, intothe input buffer 44A via the interface 43. The print data kept in theinput buffer 44A are subjected to command analysis and then transmittedto the intermediate buffer 44B. The controller 46 converts the inputprint data into intermediate codes by supplying information regardingthe printing positions of the respective letters or characters, the typeof modification, the size of the letters or characters, and the fontaddress. The intermediate codes are kept in the intermediate buffer 44B.The controller 46 then analyzes the intermediate codes kept in theintermediate buffer 44B and decodes the intermediate codes into binarydot pattern data. The binary dot pattern data are expanded and stored inthe output buffer 44C.

In any case, when dot pattern data corresponding to one scan of theprint head 10 are obtained, the dot pattern data are seriallytransferred from the output buffer 44C to the print head 10 via theparallel input-output interface 49. After the dot pattern datacorresponding to one scan of the print head 10 are output from theoutput buffer 44C, the process erases the contents of the intermediatebuffer 44B to wait for conversion of a next set of print data.

The print head 10 causes the respective nozzle openings 23 to eject inkdroplets against the printing medium at a predetermined timing, so as tocreate an image corresponding to the input dot pattern data on theprinting medium. Referring to FIG. 4, the driving signal COM generatedin the driving signal generator circuit 48 is output to the drivingcircuit 230 via the parallel input-output interface 49 and the transfercontroller 220 as discussed previously. The print head 10 has aplurality of pressure chambers 32 and the plurality of piezoelectricvibrators 17 (pressure-generating elements) respectively connecting withthe nozzle openings 23. The number of both the pressure chambers 32 andthe piezoelectric vibrators 17 is thus coincident with the number of thenozzle openings 23. When the driving signal COM is sent from the drivingcircuit 230 to a certain piezoelectric vibrator 17, the correspondingpressure chamber 32 is contracted to cause the corresponding nozzleopening 23 to eject an ink droplet.

The process of attaching the ink cartridge 107K to the cartridgeattachment unit 18 is described with referring again to FIGS. 2A, 2B,and 3. When the user operates the cartridge switch 92 b on the switchpanel 92 to give an instruction of replacing the ink cartridge 107K, thecarriage 101 shifts to a specific position that allows replacement ofthe ink cartridge 107K. The procedure of replacement first detaches theink cartridge 107K currently attached to the printer 1. A lever 192 isfixed to a rear wall 188 of the cartridge attachment unit 18 via asupport shaft 191 as shown in FIG. 3. The user pulls up the lever 192 toa release position, at which the ink cartridge 107K can be detached fromthe cartridge attachment unit 18. Another ink cartridge 107K is thenlocated on the cartridge attachment unit 18, and the lever 192 ispressed down to a fixation position, which is over the ink cartridge107K. The press-down motion of the lever 192 presses the ink cartridge107K downward, so as to make the ink supply unit 175 fitted into therecess 183 and make the needle 181 pierce the ink supply unit 175,thereby enabling a supply of ink. As the lever 192 is further presseddown, a clutch 193 disposed on a free end of the lever 192 engages witha mating element 189 disposed on the cartridge attachment unit 18. Thissecurely fixes the ink cartridge 107K to the cartridge attachment unit18. In this state, the plurality of connection terminals 174 on thestorage element 80 in the ink cartridge 107K electrically connect withthe plurality of electrodes 185 on the cartridge attachment unit 18.This enables transmission of data between the printer main body 100 andthe storage element 80. When the replacement of the ink cartridge 107Kis completed and the user operates the switch panel 92 again, thecarriage 101 returns to the initial position to be in the printablestate.

The color ink cartridge 107F basically has a similar structure to thatof the ink cartridge 107K, and only the difference is described here.The color ink cartridge 107F has five ink chambers in which fivedifferent color inks are kept. It is required to feed the supplies ofthe respective color inks to the print head 10 via separate pathways.The color ink cartridge 107F accordingly has five ink supply units 175,which respectively correspond to the five different color inks. Thecolor ink cartridge 107F, in which five different color inks are kept,however, has only one storage element 80 incorporated therein. Pieces ofinformation regarding the ink cartridge 107F and the five differentcolor inks are collectively stored in this storage element 80.

(Transmission of Information Between Ink Cartridge 107 and Printer 1)

The following describes a series of basic processing carried out by theink jet printer 1 of the embodiment from a power-on time to a power-offtime of the printer 1 and details of data transmission between thecarriage 101 and the print controller 40 with referring to theflowcharts of FIGS. 13 through 15. FIG. 13 is a flowchart showing aprocessing routine executed at a time of power supply to the printer 1.FIG. 14 is a flowchart showing a processing routine executed tocalculate the remaining quantities of inks. FIG. 15 is a flowchartshowing a processing routine executed at a power-off time of the printer1.

The controller 46 executes the processing routine of FIG. 13 immediatelyafter the start of power supply. When the power source 91 of the printer1 is turned on, the controller 46 first sets the selection controlsignal SSL output from the parallel input-output interface 49 in the lowlevel (that is, the bit data ‘0’) at step S20. This step cnables theparallel input-output interface 49 to communicate with the control IC200, in order to wait for the data transmission to and from the storageelements 80 of the ink cartridges 107K and 107F. The controller 46 thendetermines whether or not the ink cartridge 107K or 107F has just beenreplaced at step S30. The decision of step S30 is carried out, forexample, by referring to an ink cartridge replacement flag in the casewhere the EEPROM 90 has the ink cartridge replacement flag, or inanother example, based on data relating to the time (hour and minute) ofmanufacture or the production serial number with regard to the inkcartridge 107K or 107F. In the case of power-on without replacement ofthe ink cartridges 107K and 107F, that is, in the case of a negativeanswer at step S30, the controller 46 reads the data from the respectivestorage elements 80 of the ink cartridges 107K and 107F at step S31.

When it is determined that the ink cartridge 107K or 107F has just beenreplaced, that is, in the case of an affirmative answer at step S30, onthe other hand, the controller 46 increments the frequency of attachmentby one and writes the incremented frequency of attachment into thestorage element 80 of the ink cartridge 107K or 107F at step S32. Thecontroller 46 then reads the data from the respective storage elements80 of the ink cartridges 107K and 107F at step S31. The controller 46subsequently writes the read-out data at preset addresses in the EEPROM90 at step S33. At subsequent step S34, the controller 46 determineswhether or not the ink cartridges 107K and 107F attached to the ink jetprinter 1 are suitable for the ink jet printer 1, based on the datastored in the EEPROM 90. When suitable, that is, in the case of anaffirmative answer at step S34, a printing operation is allowed at stepS35 and the selection control signal SSL output from the parallelinput-output interface 49 is set in the high level (that is, the bitdata ‘1’) at step S37. This completes the preparation for printing, andthe program exits from the processing routine of FIG. 13. When notsuitable, that is, in the case of a negative answer at step S34, on thecontrary, the printing operation is not allowed, and informationrepresenting the prohibition of printing is displayed on either theswitch panel 92 or the display MT at step S36.

In the case where the printing operation is allowed at step S35, theprinter 1 carries out a predetermined printing process in response to aprinting instruction output from the computer PC. At this moment, thecontroller 46 transfers print data to the print head 10 and calculatesthe remaining quantity of each ink. The processing routine executed inthis state is described with reference to the flowchart of FIG. 14. Whenthe program enters the printing process routine shown in FIG. 14, thecontroller 46 first reads data In on the remaining quantity of each inkfrom the EEPROM 90 incorporated in the print controller 40 at step S40.The data In is written on completion of the previous cycle of printingoperation and represents the latest remaining quantity of each ink. Thecontroller 46 then inputs print data from the computer PC at step S41.In the structure of this embodiment, the required image processing likecolor conversion and binarization is all carried out by the computer PC,and the printer 1 receives the binary data with regard to apredetermined number of raster lines, that is, the on-off data of inkdots. The controller 46 subsequently calculates an amount of inkconsumption ΔI and a cumulative amount of ink consumption Ii, based onthe input print data at step S42. The amount of ink consumption ΔIcalculated here reflects not only the amount of ink consumptioncorresponding to the print data with regard to the predetermined numberof raster lines input from the computer PC but also the amount of inkconsumption by the head cleaning action including the flushing operationand the sucking operation. By way of example, the procedure ofcalculation multiplies the frequency of ejection of ink droplets by theweight of each ink droplet to calculate the quantity of ink ejectionwith regard to each ink, and adds the amount of ink consumption by theflushing operation and the sucking operation to the calculated quantityof ink ejection, so as to determine the amount of ink consumption ΔI.

The cumulative amount of ink consumption Ii can readily be computed fromthe amounts of ink consumption ΔI thus calculated. The typical procedureof computation sums up the amounts of ink consumption ΔI successivelycalculated according to the print data, so as to determine thecumulative amount of ink consumption Ii. The controller 46 then sets theselection control signal SSL output from the parallel input-outputinterface 49 in the high level at step S43. This step enables thesignals from the parallel input-output interface 49 to be output to thedriving circuit 230 via the transfer controller 220. At subsequent stepS44, the controller 46 converts the input print data to appropriate datasuitable for the layout of the nozzle openings 23 on the print head 10and the ejection timing and outputs the converted print data to theprint head 10.

When the processing of the input print data with regard to thepredetermined number of raster lines is concluded, the controllerdetermines whether or not the printing operation has been completed withregard to one page at step S45. In the case where the printing operationwith regard to one page has not yet been completed, that is, in the caseof a negative answer at step S45, the program returns to step S41 andrepeats the processing of and after step S41 to input and process a nextset of print data. In the case where the printing operation with regardto one page has been completed, that is, in the case of an affirmativeanswer at step S45, on the other hand, the program calculates thecurrent remaining quantity of each ink In+1 at S46, and writes thecurrent remaining quantity of ink In+1 thus calculated into the EEPROM90 at step S47. The current remaining quantity of ink In+1 is obtainedby subtracting the cumulative amount of ink consumption Ii determined atstep S43 from the previous remaining quantity of ink In read at stepS40. The updated remaining quantity of ink In+1 is rewritten into theEEPROM 90.

The controller 46 then sets the selection control signal SSL output fromthe parallel input-output interface 49 in the low level at step S48.This step enables the parallel input-output interface 49 to communicatewith the control IC 200 by serial communication. The latest data In+1 onthe remaining quantities of inks are then output to the control IC 200at step S49. The data on the remaining quantities of inks are notimmediately written into the storage elements 80, but are temporarilykept in the RAM 210 under the control of the control IC 200.

The updated data on the remaining quantities of the respective inks arewritten into the storage elements 80 of the black ink cartridge 107K andthe color ink cartridge 107F in response to the output of the power downinstruction NMI. The power down instruction NMI is output at thefollowing three timings as described previously:

(1) at the timing when the power switch 92 a on the switch panel 92 ofthe printer 1 is operated to turn the power source 91 off;

(2) at the timing when the cartridge switch 92 b on the switch panel 92is operated to give an instruction of replacing the ink cartridge; and

(3) at the timing when the power supply is forcibly cut off by pullingthe power plug out of the socket.

With referring to the flowchart of FIG. 15, the process of storing thedata on the remaining quantities of inks into the respective storageelements 80 of the ink cartridges 107K and 107F is described. Theprocessing routine shown in the flow chart of FIG. 15 is activated byinterruption in response to the output of the power down instruction NMIas described previously. When the program enters the processing routineof FIG. 15, it is first determined whether or not the cause of theinterruption is forcible cut-off of the power supply (the timing (3)discussed above) at step S50. In the case where the cause of theinterruption is the forcible cut-off of the power supply, that is, inthe case of an affirmative answer at step S50, the allowable time isonly little and the program accordingly skips the processing of stepsS51 through S55 and immediately proceeds to step S56. At step S56, thecontroller 46 sets the selection control signal SSL output from theparallel input-output interface 49 in the low level, so as to enable theparallel input-output interface 49 to communicate with the control IC200. The controller 46 then outputs the power down signal NMI to thecontrol IC 200 at step S57. When receiving the power down signal NMI,the control IC 200 immediately writes the updated data In+1 on theremaining quantities of inks into the respective storage elements 80 ofthe ink cartridges 107K and 107F. The updated data In+1 on the remainingquantities of inks written into the storage element 80 have beencalculated according to the processing routine of FIG. 14 andtransmitted to the control IC 200. The technique discussed above isapplied to write the data on the remaining quantities of inks into therespective storage elements 80 of the ink cartridges 107K and 107F. Thedata on the remaining quantities of inks are written and stored into thesecond storage areas 660 and 760 of the respective storage elements 80.Here the remaining quantity of each ink is alternately written into thetwo memory divisions allocated to the ink. In accordance with onepossible application, the execution of the storage into each memorydivision may be identified by means of a flag, which is located at thehead of each memory division and inverted on completion of the writingoperation into the memory division. The control IC 200 carries out thiscontrol procedure.

In the case where the cause of the interruption is not the forciblecut-off of the power supply, that is, in the case of a negative answerat step S50, on the other hand, it is determined that the interruptionis caused by either the operation of the power switch 92 a on the switchpanel 92 in the printer 1 to turn the power source 91 off or theoperation of the cartridge switch 92 b on the switch panel 92 to give aninstruction of replacement of the ink cartridge. The program accordinglycontinues the printing operation in progress by a preset unit, forexample, up to the end of one raster line, and calculates the remainingquantities of inks at step S51. The calculation is performed accordingto the flowchart of FIG. 14. The controller 46 then drives the cappingunit 108 to cap the print head 10 at step S52, and stores the drivingconditions of the print head 10 into the EEPROM 90 at step S53. Thedriving conditions here include a voltage of the driving signal tocompensate for the individual difference of the print head and acondition of correction to compensate for the difference between therespective colors. The controller 46 subsequently stores counts on avariety of timers into the EEPROM 90 at step S54, and stores thecontents of a control panel, for example, an adjustment value to correctthe misalignment of hitting positions in the case of bi-directionalprinting, into the EEPROM 90 at step S55. After the processing of stepS55, the program carries out the processing of steps S56 and S57described above. Namely the controller 46 sets the selection controlsignal SSL in the low level at step S56, and writes the updated dataIn+1 on the remaining quantities of inks into the second storage areas660 and 760 of the respective storage elements 80 of the ink cartridges107K and 107F at step S57. In the case where the power switch 92 a onthe switch panel 92 of the printer 1 is operated to activate thisinterruptive processing routine of FIG. 15, after the writing operationof the remaining quantities of inks, a signal is output to the powersource 91 to cut off the main power supply to the printer 1. In the casewhere the cartridge switch 92 b on the switch panel 92 is operated toactivate this interruptive processing routine of FIG. 15, after thewriting operation, the carriage 101 shifts to a specific position forreplacement of the ink cartridge. These processes are not specificallyshown in the flowchart of FIG. 15.

Effects of Embodiment

In the arrangement of the embodiment discussed above, the printer 1stores the information relating to the remaining quantities of inks indifferent formats of addressing in the EEPROM 90 and in the storageelements 80 of the ink cartridges 107K and 107F. Memories of adequatespecifications are thus respectively applicable for the EEPROM 90 andthe storage elements 80, based on the requirements of the storagecapacity, the speed of writing and reading operations, and the number ofsignal lines. This effectively reduces the size of the ink cartridges107K and 107F and attains the resource saving effect. The EEPROM of theserial access type is used for each storage element 80. This decreasesthe required number of signal lines in the storage element 80 andreduces the volume occupied by the signal lines, thereby reducing thesize of the ink cartridges 107K and 107F. The control IC 200 mounted onthe carriage 101 carries out the conversion of the format of addressing(8 bits, parallel) in the EEPROM 90 of the printer main body 100 into adifferent format of addressing, that is, the number of pulses of theclock signal CLK. The control IC 200 is disposed in the vicinity of thestorage elements 80 that are serially accessed. This arrangementdesirably shortens the length of the signal line connecting the controlIC 200 with each storage element 80, thereby enhancing the reliabilityof data transmission.

In this embodiment, the control IC 200 carries out the conversion of thestorage format of addressing. This arrangement favorably decreases theloading to the controller 46 included in the print controller 40. At thetime of a forcible cut-off of power supply, for example, by pulling thepower socket out of the plug, the only action required for the printcontroller 40 is to output the power down signal NMI. This extremelyshortens the time period required for the processing. This advantage isextremely significant when only a limited time period is provided forthe processing, for example, at the time of forcible cut-off of thepower supply.

In this embodiment, the data on the remaining quantities of inks arestored independently with regard to the respective inks. The control IC200 functioning as the address decoder carries out the conversion of thestorage format of addressing corresponding to a plurality of areasprovided for the respective inks in the storage elements 80. Thisarrangement enables data regarding an arbitrary ink to be immediatelyread from or written into the storage element 80 and to be immediatelywritten into or read from the EEPROM 90. When an instruction is given towrite data on the remaining quantities of inks, the control IC 200carries out the conversion of the storage format of addressing, in orderto specify one of two memory divisions alternately, which are providedfor each ink in the storage element 80. Even if data stored in one ofthe memory divisions are destroyed, this configuration enables theprocessing to be carried out accurately using the data stored in theother memory division. This enhances the reliability of the processingwith regard to the remaining quantities of inks.

The data on the remaining quantities of inks, which are finally writteninto the respective storage elements 80 of the ink cartridges 107K and107F, are temporarily registered in the RAM 210 on the control board205. This arrangement does not require the time-consuming process ofreading the respective pieces of information from the EEPROM 90 andwriting the pieces of information into the storage element 80 inresponse to each demand. This accordingly facilitates the writingoperation of data into the storage elements 80 of the ink cartridges107K and 107F. In this embodiment, the transmission of informationbetween the print controller 40 and the storage elements 80 isimplemented using the signal lines, through which the driving signal istransmitted to the respective piezoelectric vibrators 17 on the printhead 10. This arrangement desirably simplifies the configuration of thesignal lines between the print controller 40 and the carriage 101.

In this embodiment, the transfer controller 220 disposed on the controlboard 205 mounted on the carriage 101 specifies whether the input signalis to be transmitted to the driving circuit 230 or to be transmitted tothe control IC 200. The print controller 40 is thus not in charge of thefinal transmission of information. This desirably simplifies theprocessing executed by the print controller 40.

The present invention is not restricted to the above embodiment, butthere may be many modifications, changes, and alterations withoutdeparting from the scope or spirit of the main characteristics of thepresent invention. For example, ferroelectric memories (FROM) mayreplace the memory cells 81 in the storage elements 80 and the EEPROM90.

The storage elements 80 may not be incorporated in the respective inkcartridges 107K and 107F, but may be exposed to the outside. FIG. 16shows a color ink cartridge 500 having an exposed storage element. Theink cartridge 500 includes a vessel 51 substantially formed in the shapeof a rectangular parallelepiped, a porous body (not shown) that isimpregnated with ink and accommodated in the vessel 51, and a covermember 53 that covers the top opening of the vessel 51. The vessel 51 isparted into five ink chambers (like the ink chambers 107C, 107LC, 107M,107LM, and 107Y in the ink cartridge 107F discussed in the aboveembodiment), which separately keep five different color inks. Ink supplyinlets 54 for the respective color inks are formed at specific positionson the bottom face of the vessel 51. The ink supply inlets 54 at thespecific positions face ink supply needles (not shown here) when the inkcartridge 500 is attached to a cartridge attachment unit of a printermain body (not shown here). A pair of extensions 56 are integrallyformed with the upper end of an upright wall 55, which is located on theside of the ink supply inlets 54. The extensions 56 receive projectionsof a lever (not shown here) fixed to the printer main body. Theextensions 56 are located on both side ends of the upright wall 55 andrespectively have ribs 56 a. A triangular rib 57 is also formed betweenthe lower face of each extension 56 and the upright wall 55. The vessel51 also has a check recess 59, which prevents the ink cartridge 500 frombeing attached to the unsuitable cartridge attachment unit mistakenly.

The upright wall 55 also has a recess 58 that is located on thesubstantial center of the width of the ink cartridge 500. A circuitboard 31 is mounted on the recess 58. The circuit board 31 has aplurality of contacts, which are located to face contacts on the printermain body, and a storage element (not shown) mounted on the rear facethereof. The upright wall 55 is further provided with projections 55aand 55b and extensions 55c and 55d for positioning the circuit board 31.

Like the embodiment discussed above, the ink cartridge 500 of thismodified structure enables the required data, such as the data on theremaining quantities of inks, to be stored into the storage elementprovided on the circuit board 31 in a certain format of addressing,which is different from the format of addressing adopted in the EEPROM90 of the printer main body 100.

The structure of the above embodiment utilizes the transfer controller220, in order to make the signal lines to the control IC 200 completelyseparate from the signal lines to the driving circuit 230. One modifiedarrangement provides specific terminals in the control IC 200 and thedriving circuit 230 to selectively and exclusively enable the control IC200 and the driving circuit 230. In this modified structure, there is norequirement of completely separating the signals lines to the control IC200 from the signal lines to the driving circuit 230. As shown in FIG.17, this modified structure connects the signal lines to the control IC200 with the signal lines to the driving circuit 230 through wiredcommunication. The selection control signal SSL is used to exclusivelyenable either the control IC 200 or the driving circuit 230. Forexample, the high level of the selection control signal SSL enables thecontrol IC 200, whereas the low level of the selection control signalSSL enables the driving circuit 230. In this case, apart from the othersignals, the driving signal COM alone should be input directly into thedriving circuit 230. The print controller 40 outputs the signals to thecontrol IC 200 via the signal lines SG1 through SG3 when the selectioncontrol signal SSL is at the high level. The print controller 40 outputsthe signals to the driving circuit 230 via the signal lines SG1 throughSG3 when the selection control signal SSL is at the low level. Onepossible application restricts the output of the driving signal COM onlyto the case where the driving circuit 230 is enabled. In this case, theselection control signal SSL is not input into the driving circuit 230but is used only to enable the control IC 200. The piezoelectricvibrators 17 are not driven unless the driving signal COM is output.Output of the data to the signal lines SG1 through SG3 accordingly doesnot lead to the wrong activation of the driving circuit 230.

Another modified structure places the RAM 210 under the control of thetransfer controller 220 as shown in FIG. 18. The data on the remainingquantities of inks to be written into the storage elements 80 aretemporarily registered in the RAM 210, whereas recording data SI to betransferred to the driving circuit 230 are also temporarily stored inthe RAM 210 as a buffer. The recording data SI are successively suppliedto the driving circuit 230 synchronously with the clock signal CLK. Thebuffer is thus favorably used to provide data at an adequate timing.This buffer also works as the memory, in which pieces of information onthe remaining quantities of inks to be written into the storage elements80 are registered temporarily. This arrangement desirably reduces thenumber of required parts and thereby the manufacturing cost.

The timings of data transmission between the print controller 40 and thestorage elements 80 are significantly different from the timings of datatransmission between the print controller 40 and the driving circuit230. By taking advantage of the difference in timing of datatransmission, the data holding circuit 130 included in the drivingcircuit 230 may be used as the memory, in which pieces of information onthe remaining quantities of inks to be written into the storage elements80 are registered temporarily. Signal lines leading from the output ofthe data holding circuit 130 are connected with the storage elements 80,so that the data holding circuit 130 is usable as the memory, in whichthe data on the remaining quantities of inks are temporarily registered.Every time the printing operation has been concluded with regard to onepage, the data on the remaining quantities of inks are transferred asthe recording data SI synchronously with the clock signal CLK and set inthe shift registers 13A through 13N. The subsequent output of the latchsignal LAT sets the data on the remaining quantities of inks in thelatch circuit 14. When the printing operation is carried outsubsequently, the data on the remaining quantities of inks temporarilykept in the data holding circuit 130 are abandoned, and the transfer ofthe standard recording data SI resumes to control the ejection of inkdroplets from the nozzle openings 23. When the power switch 92 a on theswitch panel 92 is operated to turn the power source 91 off while thedata on the remaining quantities of inks are temporarily kept in thedata holding circuit 130 after the printing operation has been concludedwith regard to one page, the data held in the latch circuit 14 aretransferred to the storage elements 80 and written into the memory cells81 of the storage elements 80. The clock signal CLK is used as theclocks for specifying addresses in the memory cells 81. The data writteninto the memory cells 81 are generated by utilizing the output of thefinal stage 13N of the shift register circuit 13.

The above embodiment applies the five color inks, that is, magenta,cyan, yellow, light cyan, and light magenta, for the plurality of colorinks kept in the color ink cartridge. The principle of the presentinvention is, however, also applicable to another ink cartridge, inwhich any combination of an arbitrary number of different inks, forexample, six or seven different color inks, are kept. The presentinvention is further applicable to the structure in which the inkcartridges are set in the printer main body, as well as to the structurein which the ink cartridges are mounted on the carriage. The principleof the present invention may be applied to printers other than the inkjet printers, for example, laser printers using toner ink cartridges andthermal transfer printers using ink ribbon cartridges.

The scope and spirit of the present invention are limited only by theterms of the appended claims.

1. A printer comprising: a printer main body incorporating; a processingunit, and a physically separate storage device having plural pieces ofinformation about a cartridge, said cartridge, the cartridge beingdetachably attached to the printer, said cartridge comprising; an inkreservoir; a plurality of inks stored within the cartridge in the inkreservoir; a rewritable non-volatile memory containing a plurality ofpieces of corresponding information relating to said cartridge, theplural pieces of corresponding information having been written into saidnon-volatile memory less frequently than at which the plural pieces ofinformation relating to said cartridge are written into the physicallyseparate storage device incorporated in the printer main body of theprinter, and the writing of the plural pieces of correspondinginformation to said non-volatile memory of said cartridge beingtriggered based upon at least one of the following actions, operation ofa power switch, operation of a cartridge switch reflecting replacementof the cartridge, and termination of a power supply to the printer;wherein the plural pieces of corresponding information with regard tothe cartridge are written into said non-volatile memory of saidcartridge.
 2. The printer in accordance with claim 1, wherein said inkreservoir is divided into at least three ink chambers, in which at leastthree different inks are respectively kept, wherein the plural pieces ofcorresponding information at least in part correspond to quantities ofthe at least three different inks, and wherein said non-volatile memorycomprises a plurality of information storage areas, in which the pluralpieces of corresponding information corresponding to quantities of theat least three different inks are stored respectively and independently,and wherein each of the plurality of information storage areas has astorage capacity of at least one byte.
 3. The printer in accordance withclaim 1, wherein said non-volatile memory has a specific writing area,in which the plural pieces of corresponding information are written, onone end of a memory space thereof.
 4. The cartridge as in claim 1,wherein the physically separate storage device of the printer is anon-volatile memory.
 5. The cartridge as in claim 2, wherein thephysically separate storage device of the printer is a non-volatilememory.
 6. The cartridge as in claim 3, wherein the physically separatestorage device of the printer is a non-volatile memory.